220 THE ZOOLOGIST. 



the other also. The fact that some birds make no nests at all, 

 or do so in such a slovenly fashion that they might just as well 

 not, or that, in some cases, the nest is put to another and 

 totally different use (as I have now shown to be the case) is not 

 urged as an argument against the undeniable relation which it 

 has to egg-laying and incubation in other cases, or in these 

 also ; but it is thought that because the sexual antics of some 

 birds make but a poor sort of display, or do not seem designed to 

 that end, or not exclusively so, or are performed by dull-coloured 

 species, therefore the most highly developed and finished exhibi- 

 tions, carefully gone through by the most beautiful male birds of 

 the world, who thus show off their best points to the best advantage 

 before the females, and may be seen actually to win them by so 

 doing, are not real courtships, or real courting displays, either — 

 even though they may have to be called so.* But if it is out of a 

 number of odd, uncouth, violent, and wholly unintelligent move- 

 ments made by male birds (for the most part) during what I have 

 called the sexual frenzy, that Natural (here called sexual) Selection 

 has, through the consequent excitation of the female, gradually 

 evolved the true nuptial display, this state of things is precisely 

 what we might expect — in fact, ought to find, and the argument 

 is quite parallel as applied to the stages of nidification. What 

 the objection to this view is I really do not know. It cannot 

 surely be supposed that here alone we should find the crown of 

 the edifice only, the flower without its stalk. It is in accordance 

 with the principle of evolution that there should be a passage from 

 the simple to the complex, from the generalized to the specia- 

 lized ; and out of what, more naturally, should the movements 

 of sexual display have arisen than out of sexual movements ? 

 As to the contention that because a male bird is dull-coloured it 

 cannot, through pose and exhibition, make the best even of its 

 dullness, and thus produce a greater or lesser degree of sexual 

 excitation in the female — or vice versa — I have never been able 

 to follow it. The concupiscent element seems to be forgotten 

 by those who make this objection, and also that aesthetic percep- 



* Because they so obviously are. In the case of the Blackcock I have 

 actually seen the hen won by the courtship of particular birds, though by far 

 the greater number were resisted. "Besisted" is the right word, for the 

 effect of the display, as such, was always apparent. 



